1. Field of the Invention
The present invention relates to a protective sheath or safety guard for winged needles and, in particular, to a protective sheath having a keyhole for releasably retaining the flexible tubing of a winged needle set and a method of packaging a winged needle set having such a protective sheath.
2. State of the Art
A well known winged needle (also known as a butterfly needle) assembly is shown in prior art FIG. 1. The assembly 10 includes a needle 12 having a pair of wings 14, coupled to a first end of a length of coiled flexible tubing 16, and a coupling attached to the rear end of the tubing by which this winged needle set or assembly may be attached to, e.g., means for piercing a vacuum bottle for blood collecting or a Luer lock tapered coupling for IV tubing. The winged needle assembly has been used for many years in, e.g., the administration of IV medications and in obtaining blood samples when use in conjunction with vacuum bottles. The purpose of the assembly is to limit trauma to the patient's blood vessel(s), particularly-when multiple samples of blood are to be taken or when multiple types of medication are to be administered. After the needle is inserted into the patient's blood vessel, the wings are taped to the patient's body to prevent movement of the needle when coupling/uncoupling the Luer lock or attaching or disconnecting the vacuum bottle used for blood collecting. Any movement of the needle can cause trauma of the patient's blood vessel. The winged needle assemblies are typically packaged with the flexible tubing wound in a coil such as illustrated in FIG. 1, typically coiled in several loops. It has recently been discovered by the inventor herein that when a winged needle kit is packaged with the tubing coiled, the tubing tends to retain a coiled configuration even after it is unpackaged. It has also been discovered by the inventor herein that when the flexible tubing has retained a coiled configuration, even a slight movement of one end of the tubing will disadvantageously cause immediate movement of the other end.
In the 1980s after the discovery of the HIV virus which causes AIDS, much attention was given to the problem of accidental needlesticks from contaminated medical equipment such as syringes and IV equipment, which poses serious risks to healthcare professionals. Even maintenance personnel who dispose of the used medical equipment are at risk. Hepatitis, AIDS and other diseases can be, and sometimes are, transmitted by accidental needlesticks from needles used on infected patients.
My prior U.S. Pat. No. 5,330,438 discloses an improved sheath construction (shown in prior art FIG. 2) which significantly minimizes the possibility of improper operation and jamming of the used needle relative to the sheath during the sheathing operation. The IV infusion set 20 includes an IV tube 22, a hollow needle 24 coupled to one end of the tube and two wings 26 adjacent the needle 24. A Luer connector (not shown) is connected to the other end of the IV tube. The IV infusion set 20 also includes a sheath 28 slidably disposed on tube 22. The sheath 28 is adapted to be slid past the flexible wings 26 to cover the needle after the needle has been used.
The sheath 28 preferably includes a knurled, generally cylindrical, annular base 29 by which the sheath may be easily grasped. Base 29 has a central bore (not shown) through which tube 22 may slidably pass and is integrally joined to a hollow generally tubular body 30 having a forward end 32 oriented toward the needle 24 and a rearward end 34 oriented away from the needle. The body 30 preferably has four fingers 35 separated by four longitudinally extending slots 36 extending from the forward end or tip 32 of body 30 to the rearward end 34. The slots 36 are each adapted to receive only one of the wings 26 to allow at least part of the sheath 28 to be slid past the wings 26 to cover the needle 24.
The body 30 also includes cutouts 42 at the rearward end of the slots 36, adapted to receive and engage the wings 26 to lock the sheath in its position covering the needle. The cutouts 42 have a width approximately equal to the width of one of the wings 26. Slot 36 is slightly narrower than the thickness of the wings. As a result, as the wings 26 pass through the slots 36, the fingers 35 will resiliently wedge apart, and upon passage of the wings 26 into the wider cutouts 42, snap back and assume their normal position, thereby trapping the wings 26 in the cutouts 42 behind the forward edges 44 of the cutouts. This prevents the needle 24 from sliding forwardly out of the sheath 28.
Recently, the U.S. Food and Drug Administration has requested that all safety devices used with needles either change color or produce an audible sound or provide some other easy to recognize evidence that the needle has been rendered safe. My prior application 20020188260 addresses that concern and provides other improvements.
FIGS. 3 and 4 illustrate the needle sheath of said published application. The sheath 128 is provided in conjunction with a hollow needle 124 with a pair of wings 126. The sheath 128 includes at least a pair of fingers 132, 140 extending from an annular base 130. (FIG. 4 illustrates an embodiment 128′ with four fingers 132′, 133, 140′, 141). The fingers define a pair of slots 142 through which the wings 126 of the needle 124 may slide. The slots define an open end 146 and a closed end 154. The slots 142 are provided with a Z-bend 153, 155. The Z-bend is dimensioned such that the wings 126 can pass through it with some deformation, and an audible click is heard as the wings and/or fingers cease to be deformed. As seen in FIG. 3, the fingers 132, 140 terminate in a first annular structure 138 which is separated from the annular base 130 by a hilt 134. As shown in FIG. 3, the hilt 134 has two angled ends 150, 152, although the angled ends may be omitted as shown in FIG. 4 at 134′. The hilt 134 assists in holding the sheath while sliding the sheath and of the wings into the locked position shown in FIG. 3.